A 6.0-magnitude earthquake has hit northern Italy, reportedly killing at least seven people and injuring 50 others. One of the strongest quakes was followed by a series of powerful aftershocks causing more damage.

The initial 4.2-magnitude tremor struck a populated region in the north of the country at 01:13 am (23:13 GMT). It was followed by a strong, 6.0-magnitude aftershock, which affected the cities of Modena, Ferrara, Verona and Mantua. Thousands of people flooded the streets following the quake, local mayors warning people to stay out of their homes.

The epicenter of the second quake, which was registered near the township of Camposanto, was located at a relatively shallow depth of 10.1 km. It was followed by two powerful aftershocks of 5.1 and 4.7-magnitude in the same area.

Some 10 hours after the first quake, an aftershock of 4.5-magnitude struck near the township of San Felice sul Panaro.

The latest aftershock of 5.1-magnitute occurred about 12 hours after the initial quake, causing more buildings to collapse.

This comes as authorities ordered the evacuation of some 3,000 people from the earthquake-affected area.

The head of the region Vasco Errani has also called on the government to impose a state of emergency across the country. His motion was backed by the authorities from a neighboring region.

The state of emergency may be imposed on Tuesday after the scheduled meeting of the cabinet.

Local officials say one man died in the locality of Bordeno when a warehouse collapsed during the quake. Two others were killed in a cave-in at a ceramics factory in Sant’Agostino di Ferrara and another victim was found underneath the rubble of local business Tecopress di Dosso.

Three women have also died of heart attacks, triggered by shock during the earthquake, report Italian authorities.

Footage of the areas hit by the quake showed widespread damage to historic buildings: roofs collapsed, church towers showed cracks and the bricks of some walls tumbled into the street.

"It's in the Bologna-Ferrara area. There's been a bit of damage; some structures have come down with people in them," an eyewitness in Ferrara told Reuters news agency.

Rescue teams are now scouring the wreckage amid fears there may be some people trapped underneath the rubble.

Italy frequently experiences seismic movements, but strong earthquakes are relatively rare. The latest major earthquake to occur hit the central Italian city of L’Aquila in 2009, killing almost 300 people.

Epicenter of the quake

AFP Photo / Giuseppe Cacace

AFP Photo / Pierre Teyssot

AFP Photo / Pierre Teyssot

AFP Photo / Pierre Teyssot

AFP Photo / Pierre Teyssot

AFP Photo / Giuseppe Cacace

AFP Photo / Pierre Teyssot

Elderly people take a rest after being evacuated to a sports center in Finale Emilia (AFP Photo / Pierre Teyssot)